The present invention relates to Japanese application No. 11 366142 filed Dec. 24, 1999, which is incorporated by reference herein and from which priority is claimed.
The present invention is one that relates to a performance position retrieval system that is installed in, for example, electronic musical instruments.
Automatic performance systems that, in the case of the performance of a musical composition with an electronic musical instrument, automatically track the performance by the performer with a musical accompaniment are known. With regard to this tracking, the automatic performance tracking system detects the position of the composition that is performed and an automatic performance is carried out with, for example, a musical accompaniment that coincides with the performance and which matches the tempo of the performance. Accordingly, it is necessary for the automatic performance tracking system to accurately search at that instance, from the performance data that is performed, to determine the position in the composition of the performance.
According to one known method for an automatic performance tracking system to retrieve the position of a composition that is being performed, the automatic performance tracking system compares in detail the line of musical tones (notes; hereafter, referred to as the xe2x80x9cnote linexe2x80x9d) for the most recent multiple number of note lines that have been performed with the note lines on the music score as well as the pitch and length of each of these notes and the point where the performed note line and the note line on the music score are in agreement. That point is considered the performance position.
With the methods of the past, since the automatic performance tracking system had to compare and validate the performed note line and the note line on the music score from the beginning of the composition for each performance (for example, for each key pressing), the retrieval speed was slow. In addition, there have been weaknesses in the accuracy of judgment, in a case where there are a multiple number of locations in the composition where there is agreement, of which of the locations that agree should be determined to be the performance position.
The present invention takes the relevant problems into consideration and has as its object making it possible to search rapidly and more accurately for a position in a musical composition that the performer, etc., is currently performing.
In order to solve the problems discussed above, the electronic musical instrument performance position retrieval system that is related to the present invention is, in its basic form, provided with an automatic performance means in which the performance data for the musical composition are stored and an automatic performance is carried out in accordance with that performance data, an input means in which the performer inputs the performance data for the performance and a retrieval table with which a prescribed computation is carried out for a sequence of a specified amount of performance data from the above mentioned performance data for the musical composition. Demarcation is done in accordance with the computation results and the position information is stored. A retrieval means, in which the above mentioned prescribed computation is carried out for a sequence of the performance data that have been input in the above mentioned input means, retrieves the performance position based on the above mentioned retrieval table in accordance with the results of the computation.
In addition, this performance position retrieval system can be configured so that it is provided with a means in which, for the position information that has been retrieved based on the above mentioned retrieval table, verification is done with prescribed retrieval rules and the performance position is determined.
With this performance position retrieval system, the retrieval table is formed by taking a sequence of the performance data (performance data that are continuous or that skip an amount etc.), carrying out a prescribed computation such as a hash function with these, making the demarcation of the performance data line in accordance with the results of the computation and storing their position information in the musical composition. This position information can be made so that it is, for example, the position information in a musical composition for the performance data that have been input most recently in a sequential performance data line.
When the performer successively inputs the musical tone performance data with an input means such as a keyboard, a prescribed computation is successively carried out by the retrieval means on the sequence of performance data that have been successively input. The retrieval table is then searched based on the results of the computation. Then, one or a multiple number of items of position information are fetched in accordance with the computation results and the performance position of the performer is retrieved.
With this performance position retrieval, it is possible for the performer to infer the performance position in the musical composition that is being performed with the position information that have been selected in accordance with prescribed retrieval rules for the one or multiple number of items of position information that have been, for example, fetched from the retrieval table.
Here, the above mentioned retrieval rules can be formulated, such as, for example, the following.
(1) If the position information that has been retrieved is within xc2x1xcex1 (xcex1 is, for example, one bar etc.) of the current position in the automatic performance, that position information is ignored.
(2) If the items of position information that have been retrieved are prior temporally to the current position in the automatic performance, the position information that is closest to the current position is selected.
However, if the most proximate items of position information are both within xcex2 (xcex2 is, for example, two bars), the position information that is further in front temporally (nearer the beginning of the composition) is selected.
(3) If the items of position information that have been retrieved are only temporally after the current position in the automatic performance, the position information that is closest to the current position is selected.
In addition, if this performance position retrieval system is provided with a transfer means in which the performance position of the automatic performance is transferred to the performance position that has been assumed by the above mentioned assumption means, it is possible for it to automatically track the performance position of the performer.